The primary aim of this study is to demonstrate the role of paroxetine in the acute treatment of chronic primary insominia. It is hypothesized that paroxetine taken on a nightly basis in combination with sleep hygiene therapy will produce a greater number of diagnostic responders in acute treatment, compared to placebo and sleep hygiene control condition, in a randomized, double-blinded, six-week acute treatment trial. EEG sleep, sleep quality, daytime well-being and daytime functioning will also show superior treatment effects during acute treatment with paroxetine plus sleep hygiene, as compared with the placebo control condition. The impact of stress and mood on response to treatment will also be evaluated.